AUS LOESBAR MITEINANDER VERBUNDENEN ELEMENTEN BESTEHENDES BOHRGESTAENGE

摘要

A drill element in the form of a drill rod, a sleeve for coupling together two drill rods or a drill bit; the drill element having a single start internal or external cylindrical screw thread by which it is intended to be coupled to a further drill element in the assembly of a drill string for percussion or rotary/percussion drilling.